autoinsert: add multiple cursors support (#36)

adds the functionality for multiple cursors as well as matching the behavior of sublime/vscode more closely

Co-authored-by: Lore M <maierulorenzo@gmail.com>

Author: loremdifr

manifest.json

@@ -221,9 +221,9 @@
     {
       "description": "Automatically inserts closing brackets and quotes. Also allows selected text to be wrapped with brackets or quotes.",
       "id": "autoinsert",
-      "mod_version": "3",
+      "mod_version": "3.1",
       "path": "plugins/autoinsert.lua",
-      "version": "0.2"
+      "version": "0.3"
     },
     {
       "description": "Automatically saves files when they are changed",

plugins/autoinsert.lua

@@ -1,4 +1,4 @@
--- mod-version:3
+-- mod-version:3.1
 local core = require "core"
 local translate = require "core.doc.translate"
 local config = require "core.config"
@@ -8,24 +8,33 @@ local command = require "core.command"
 local keymap = require "core.keymap"
 
 
-config.plugins.autoinsert = common.merge({ map = {
-  ["["] = "]",
-  ["{"] = "}",
-  ["("] = ")",
-  ['"'] = '"',
-  ["'"] = "'",
-  ["`"] = "`",
-} }, config.plugins.autoinsert)
+config.plugins.autoinsert = common.merge({
+  map = {
+    ["["] = "]",
+    ["{"] = "}",
+    ["("] = ")",
+    ['"'] = '"',
+    ["'"] = "'",
+    ["`"] = "`",
+  }
+}, config.plugins.autoinsert)
 
 
+-- @param chr stirng
+-- @return boolean
 local function is_closer(chr)
   for _, v in pairs(config.plugins.autoinsert.map) do
     if v == chr then
       return true
     end
   end
+  return false
 end
 
+
+-- @param text stirng
+-- @param chr stirng
+-- @return number
 local function count_char(text, chr)
   local count = 0
   for _ in text:gmatch(chr) do
@@ -35,87 +44,178 @@ local function count_char(text, chr)
 end
 
 
-local on_text_input = DocView.on_text_input
+-- @param dv DocView
+-- @param idx number
+-- @param text string
+-- @param mapping string
+-- @return boolean
+local function on_text_input_cursor(dv, idx, text, mapping)
+  local l1, c1, l2, c2 = dv.doc:get_selection_idx(idx, true)
+  local is_selection_empty = not (l1 ~= l2 or c1 ~= c2)
 
-function DocView:on_text_input(text)
+  -- wrap selection if we have a selection
+  if mapping and not is_selection_empty then
+    dv.doc:insert(l2, c2, mapping)
+    dv.doc:insert(l1, c1, text)
+    dv.doc:set_selections(idx, l1, c1 + 1, l2, c2 + 1, true)
 
-  -- Don't insert on multiselections
-  if #self.doc.selections > 4 then return on_text_input(self, text) end
+    return true
+  end
+
+  -- no selections, check char next to cursor
+  local chr = dv.doc:get_char(l1, c1)
 
+  -- skip inserting closing text if already there,
+  -- instead just move the cursor to the right of the chr
+  if text == chr and is_closer(chr) then
+    dv.doc:move_to_cursor(idx, 1)
+    return true
+  end
+
+  -- don't insert closing quote if we have a non-even number on this line
+  if text == mapping and count_char(dv.doc.lines[l1], text) % 2 == 1 then
+    return false
+  end
+
+  -- auto insert closing bracket
+  -- checks that character next to the cursor is:
+  -- either whitespace (%s) or the mapped closer character.
+  -- and it's not a double quote character ('"')
+  if mapping and (chr:find("%s") or is_closer(chr) and chr ~= '"') then
+    dv.doc:insert(l1, c1, text)
+    dv.doc:insert(l2, c2 + 1, mapping)
+    -- move inside the bracket pair:
+    dv.doc:move_to_cursor(idx, 1)
+    return true
+  end
+
+  return false
+end
+
+
+-- save the original on_text_input to call it later
+local on_text_input = DocView.on_text_input
+
+function DocView:on_text_input(text)
   local mapping = config.plugins.autoinsert.map[text]
 
   -- prevents plugin from operating on `CommandView`
   if getmetatable(self) ~= DocView then
     return on_text_input(self, text)
   end
 
-  -- wrap selection if we have a selection
-  if mapping and self.doc:has_selection() then
-    local l1, c1, l2, c2, swap = self.doc:get_selection(true)
-    self.doc:insert(l2, c2, mapping)
-    self.doc:insert(l1, c1, text)
-    self.doc:set_selection(l1, c1, l2, c2 + 2, swap)
+  -- call auto insert on every selection
+  for idx in self.doc:get_selections() do
+    local inserted = on_text_input_cursor(self, idx, text, mapping)
+
+    -- operate normally on the cursor when nothing was inserted
+    if not inserted then
+      self.doc:text_input(text, idx)
+    end
+  end
+end
+
+-- this deletes the matching pair when backspacing the opening one
+-- @param doc DocView.doc
+-- @param idx number
+local function delete_matching_pair(doc, idx)
+  local l1, c1, l2, c2 = doc:get_selection_idx(idx, true)
+
+  -- skip backspace if at the beginning of the line
+  if c1 <= 1 then
     return
   end
 
-  -- skip inserting closing text
-  local chr = self.doc:get_char(self.doc:get_selection())
-  if text == chr and is_closer(chr) then
-    self.doc:move_to(1)
+  -- only do it if there's nothing selected for the cursor
+  local is_selection_empty = not (l1 ~= l2 or c1 ~= c2)
+  if not is_selection_empty then
     return
   end
 
-  -- don't insert closing quote if we have a non-even number on this line
-  local line = self.doc:get_selection()
-  if text == mapping and count_char(self.doc.lines[line], text) % 2 == 1 then
-    return on_text_input(self, text)
+  -- check if the character to the right of the one being deleted
+  -- is the expected matching pair
+  local chr = doc:get_char(l1, c1)
+  local mapped = config.plugins.autoinsert.map[doc:get_char(l1, c1 - 1)]
+  if mapped and mapped == chr then
+    -- delete 1 more character
+    doc:remove(l1, c1, l2, c2 + 1)
   end
+end
 
-  -- auto insert closing bracket
-  if mapping and (chr:find("%s") or is_closer(chr) and chr ~= '"') then
-    on_text_input(self, text)
-    on_text_input(self, mapping)
-    self.doc:move_to(-1)
-    return
+-- @param doc DocView.doc
+local function on_backspace(doc)
+  for idx in doc:get_selections() do
+    delete_matching_pair(doc, idx)
+  end
+  -- execute the backspace normally
+  command.perform "doc:backspace"
+end
+
+-- need this because the doc:backspace already operates on all cursors,
+-- we only want to do it on a single cursor
+local function perform_backspace_cursor(doc, idx)
+  local _, indent_size = doc:get_indent_info()
+  local line1, col1, line2, col2 = doc:get_selection(idx, true)
+  if line1 == line2 and col1 == col2 then
+    local text = doc:get_text(line1, 1, line1, col1)
+    if #text >= indent_size and text:find("^ *$") then
+      doc:delete_to_cursor(idx, 0, -indent_size)
+      return
+    end
   end
+  doc:delete_to_cursor(idx, translate.previous_char)
+end
 
-  on_text_input(self, text)
+-- @param doc DocView.doc
+local function on_delete_to_previous_word_start(doc)
+  for idx in doc:get_selections() do
+    local le, ce = translate.previous_word_start(
+      doc, doc:get_selection_idx(idx, true))
+    ce = ce + 1 -- dont over delete
+    repeat
+      local l, c = doc:get_selection_idx(idx, true)
+
+      -- delete character and matching pair if any
+      -- we dont call on_backspace because that already operates on every cursor.
+      delete_matching_pair(doc, idx)
+      perform_backspace_cursor(doc, idx)
+    until l <= le and c <= ce
+  end
 end
 
 
+-- @param doc DocView.doc
+local function on_delete_to_start_of_line(doc)
+  for idx in doc:get_selections() do
+    local le, ce = translate.start_of_line(
+      doc, doc:get_selection_idx(idx, true))
+    ce = ce + 1 -- dont over delete
+    repeat
+      local l, c = doc:get_selection_idx(idx, true)
+
+      -- delete character and matching pair if any
+      -- we dont call on_backspace because that already operates on every cursor.
+      delete_matching_pair(doc, idx)
+      perform_backspace_cursor(doc, idx)
+    until l <= le and c <= ce
+  end
+end
+
 
 local function predicate()
-  return core.active_view:is(DocView)
-    and #core.active_view.doc.selections <= 4 and not core.active_view.doc:has_selection(), core.active_view.doc
+  return core.active_view:is(DocView), core.active_view.doc
 end
 
+
 command.add(predicate, {
-  ["autoinsert:backspace"] = function(doc)
-    local l, c = doc:get_selection()
-    if c > 1 then
-      local chr = doc:get_char(l, c)
-      local mapped = config.plugins.autoinsert.map[doc:get_char(l, c - 1)]
-      if mapped and mapped == chr then
-        doc:delete_to(1)
-      end
-    end
-    command.perform "doc:backspace"
-  end,
-
-  ["autoinsert:delete-to-previous-word-start"] = function(doc)
-    local le, ce = translate.previous_word_start(doc, doc:get_selection())
-    while true do
-      local l, c = doc:get_selection()
-      if l == le and c == ce then
-        break
-      end
-      command.perform "autoinsert:backspace"
-    end
-  end,
+  ["autoinsert:backspace"] = on_backspace,
+  ["autoinsert:delete-to-previous-word-start"] = on_delete_to_previous_word_start,
+  ["autoinsert:delete-to-start-of-line"] = on_delete_to_start_of_line,
 })
 
 keymap.add {
   ["backspace"]            = "autoinsert:backspace",
   ["ctrl+backspace"]       = "autoinsert:delete-to-previous-word-start",
-  ["ctrl+shift+backspace"] = "autoinsert:delete-to-previous-word-start",
+  ["ctrl+shift+backspace"] = "autoinsert:delete-to-start-of-line",
 }
+